India, Sept. 4 -- The United Nations climate chief has called on world leaders to announce ambitious new climate targets at a special high-level event in New York on September 24, as the world races against time to avert catastrophic global warming.

In a letter sent Wednesday to 196 parties of the Paris Agreement, Simon Stiell, executive secretary of the UN Framework Convention on Climate Change (UNFCCC), urged all nations to submit their enhanced Nationally Determined Contributions (NDCs) by the end of September.

"Around 190 countries have indicated they will submit their new NDCs this year or have already submitted," a UNFCCC spokesperson said, highlighting the global momentum behind the climate action drive.

The submissions deadline...